Twin calorimeter for the determination of enthalpies of vaporization of small samples from 300 to 420 K

Abstract

A twin enthalpy of vaporization calorimeter of the adiabatic isothermal type has been designed, built and tested. The substance, 5–20 mg, enclosed in ampoules, is completely vaporized into a vacuum through a small aperture. The vaporization is performed isothermally at preselected temperatures which may vary between room temperature and 420 K. The calorimeter has been tested by measuring the enthalpies of vaporization of n-tridecane, n-tetradecane and n-pentadecane.